1. Field of the Invention
This invention relates to devices for cleaning the bottoms of boats while the boats are in the water, and more particularly to such cleaning devices having a bouyant floatation scrubbing head tending to rise in the water against the bottom of the boat.
2. Description of the Prior Art
Numerous efforts have been made to devise a boat bottom scrubber manipulatable from an adjacent dock or the like and in which the scrubbing apparatus is buoyant so it will float up against the bottom of the boat and facilitate the cleaning action. Typical of such devices are the implements disclosed in U.S. Pat. No. 3,010,420 issued Nov. 28, 1961 to James C. Glynn, which shows a rectangular block of buoyant material having a brush fastened to it and designed for manipulation by a handle having a joint in the middle intended to be held in desired position by a thumbscrew; U.S. Pat. No. 4,407,213, issued Oct. 4, 1983 to Peter R. Evans, which discloses a hollow cleaning head with a filler aperture enabling water to be introduced into the head to vary the buoyancy thereof, the cleaning head being mounted on a handle having a hinge intended to be held at a desired angle by a thumbscrew; and U.S. Pat. No. 2,720,858, issued Oct. 18, 1955 to Stuart B. Siefken, which shows a cylindrical tank mounted on the end of a straight handle and having a brush attached to the side of the tank.
Hinged handles such as those shown in the Glynn and Evans patents are not capable of holding two sections of a handle at a desired angle under the extreme conditions encountered while scrubbing plants and slime from the bottoms of boats.
A somewhat different approach to the problem of controlling the scrubbing head is illustrated in U.S. Pat. No. 4,060,047 issued Nov. 29, 1977 to Barney Sabella, this device also having thumbscrews to hold sections of a handle at a desired angle to each other, and having a bristle brush and a scraping head intended to be aligned with the bottom of the boat by elongated stabilizing members which contact the boat.
Another approach to a floatation scrubber is found in U.S. Pat. No. 4,648,344 issued Mar. 10, 1987 to John Burgers et al , and U.S. Pat. No. 4,781,139 issued Nov. 1, 1988 to John Burgers. Both of these patents show an elongated flexible strip which is buoyant and which carries a sheet of scrubbing material on its upper side for contact with the boat. The flexible, buoyant strip is manipulated by a straight handle.
U.S. Pat. No. 4,909,173 issued Mar. 20, 1990 to Dwight J. Strong shows a scrubbing device in which the scrubbing head does not depend on buoyancy to urge it against the bottom of the boat, this being accomplished by a vane on the scrubbing head inclined in such manner as to force the scrubbing head against the bottom of the boat as it is moved therealong.
U.S. Pat. No. 4,733,427 issued Mar. 29, 1988 to Richard H. Conrad, shows a swimming pool brush having an inclined vane for urging it against the bottom and sides of the swimming pool, while U.S. Pat. No. 630,261 issued Aug. 1, 1899 to George A. McLane showing a barnacle scraper mounted on a straight pole and having a brush along its triangular edge.
The above-listed patents are believed to be relevant to the present invention because they were adduced by a prior art search made by an independent searcher, and a copy of each of the above-listed patents is supplied to the Patent and Trademark Office herewith.